6 Career Lessons You Need To Learn In Your 20s

These initiatives have included the Athena Center for Leadership Studies, an interdisciplinary center devoted to the theory and practice of women's leadership, and Barnard's Global Symposium series, an annual gathering of high-profile and accomplished female leaders held each year in a different region of the world.

She has become one of the top voices for women's leadership and recently released her newest book, Wonder Women: Sex, Power, and the Quest for Perfection. Her book tackles the ongoing myth of solitary perfection by examining where women are today in the workforce and in power circles using both data and personal anecdotes. She is very open about her experiences and mishaps, including the time she wore a pink suit to her first interview at Harvard or when she crashed the family minivan while trying to retrieve her child's ballet costume.

Spar joined Levo League for Office Hours to share the top lessons from her book:

1. Life is not linear.

Many women, especially young women who are just beginning their careers, presume that if you make the right set of decisions, you will follow one specific path towards success easily and seamlessly. However, Spar argues that a majority of the successful people that she knows had no inclination in their early professional life that they would wind up in the positions they did further into their careers.

"Life proceeds in zigzags," she said. "You really can't figure out early in your life how to get from point A to point B. Instead, I would say be ready for the zigzags. Find jobs that you like doing. You probably won't love your job at 24 — to be honest most people by definition don't have their dream job at 24."

However, when facing uncertainty in your life path or career, it is also important not to do anything sudden or rash. Rather, Spar suggests that you try to determine what most interests you, what you're best at, what other role models or aspirations you might have, and move slowly. Often times if you're deciding to make a big career jump, say from one industry to another, go for job interviews you don't necessarily want in that new function. This will provide you with the opportunity to perfect your interviewing skills and to articulate what your motivations are for this new type of position.

2. You can't do it all.

No woman, man, or human can do it all. It's that simple. Spar believes that we have somehow developed a misconception that not only can women have it all, but women should in fact do it all.

"That's just a myth and it's a dangerous myth," said Spar. "I would encourage all young women to think about making choices because that's what life is really about…Look at those choices as broadly as you can and make those choices as carefully and consciously as you can."

Spar emphasizes that when you make these life choices and say yes to one change, it is essential that you say no to something else. Women fall into trouble when they try to do too much.

"I have discovered that it is much easier to say no than to say maybe," she said. "Maybe is what gets you into trouble. Maybe is what makes you feel guilty and worried and sad."

3. Own up to mistakes.

None of us are perfect and all of us, men and women alike, are going to make mistakes — fairly frequently. Ideally these mistakes will be small and fixable, but sometimes they will be big and you won't necessarily be able to remedy them. However, rather than falling to pieces or getting discouraged, take ownership, acknowledge that a mistake was made, ask how you can fix it, learn from it, and move on.

"Making mistakes does not make you a failure. Making mistakes means just that — you've made a mistake," she said. "Get comfortable with screwing up and get comfortable with acknowledging that you've screwed up."

4. Look for sponsors.

Spar agrees with economist Sylvia Ann Hewlett that women should not just be looking for mentors, but also for sponsors. These will be the people who are not necessarily assigned to you to provide advice from time to time, but also take an active interest in furthering your career. If these sponsors don't exist within your immediate network, reach out and actively solicit people's feedback.

These sponsors are not only your cheerleaders, but also your teachers and at times your critics. Spar explained that one of the greatest things that happened in her career was that she had four or five sponsors in her life, all of whom happened to be men. They provided her with criticism on a very consistent basis, which was challenging but also an incredible learning experience.

"It wasn't fun," Spar said. "I didn't like it when I was going through it, but they were giving me criticism because they were taking an interest in me and my career."

5. Don't personalize office politics or professional criticism.

Everyone will face criticism in their careers. We all have bad days, but try as much as you can to take it in stride, smile through it, and don't take it personally.

"We all constantly feel like we're failing. If you think about it, nobody is perfect. If we're lucky, we have perfect moments in our lives, maybe perfect days, or maybe a perfect meal," Spar said. "If we set the standard at perfection, then we are constantly falling short of it. We are preordaining ourselves to fail and that's a horrible place to be."

6. Be good at what you do.

Ultimately women are going to get promoted and they are going to advance in their careers, if they are good at what they do. There is no amount of networking or mentors or sponsorship that can make up for simply being good at you job. Take your job seriously, even if it's not your dream job, get good at it, and that will be the single most important factor in shaping your success.

"Remember that this is supposed to be fun," said Spar. "The goal of liberation for women, the objective of opening up so many opportunities for women really was to bring joy into our lives to liberate us."